A new composite structure full back heterojunction solar cell and its preparation method

Abstract

The invention discloses a novel composite structure full-back heterojunction solar cell and a preparation method thereof. The solar cell includes: an N-type silicon substrate, a silicon nitride film, an aluminum oxide film, intrinsic polysilicon, P-type polysilicon, N-type polysilicon; the front surface of the N-type silicon substrate is covered with an aluminum oxide film, and the aluminum oxide film is covered with a silicon nitride film; the back surface of the N-type silicon substrate is deposited with intrinsic polysilicon P-type polysilicon and N-type polysilicon. In the present invention, the polysilicon layer is deposited by the LPCVD of the horizontal slice mode or the PECVD of the horizontal slice type, and the homogeneous junction layer can effectively reduce the interface defect state and reduce the interface recombination; the laser doping technology is used to realize the doping of the P-type polysilicon layer, and the maximum Maximize the minority carrier life of the silicon substrate and reduce the recombination current density of the metal-silicon contact; at the same time, the battery with the IBC structure allows the battery to make full use of the solar spectrum and maximize the short-circuit current density of the battery.

Description

technical field [0001] The invention relates to the technical field of manufacturing crystalline silicon solar cells, in particular to a novel composite structure full-back heterojunction solar cell and a preparation method thereof. Background technique [0002] At present, the mainstream technology of mainstream crystalline silicon solar cells is based on polycrystalline black silicon and PERC structure cells. The basic process consists of texturing, diffusion, etching, deposition of anti-reflection film, and screen printing methods on P-type and N-type silicon substrates. Make solar cells. However, the performance of P-type crystalline silicon cells will decline under the influence of oxygen. With the continuous tightening of the global photovoltaic subsidy policy, the market demand for high-performance batteries is becoming more and more strong, while N-type batteries contain less boron, and the performance stability is higher than that of P-type crystalline silicon batt...

AI Technical Summary

Problems solved by technology

[0004] 1) When the silicon wafer is placed on the positioning card point, it is inevitable to rub and cause scratches and reduce battery efficiency;

[0005] 2) Due to the inclination of the silicon wafer, the gap between the back of the silicon wafer and the graphite plate is relatively large, which can easily cause the phenomenon of winding plating and reduce the efficiency of the battery, and even cause abnormal leakage;

[0006] 3) The silicon wafer is blocked by the positioning card point to a certain extent, which hinders the deposition of the process gas, and will show a very shallow or non-coated surface, resulting in poor coating, such as unsightly appearance and reduced resistance to metal pollution;

[0007] 4) If the silicon chip breaks and touches the opposite plate, it will cause a short circuit and poor workmanship

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